The present invention relates to pre-heater assemblies for pre-heating a fluid, to a fluid separation apparatus, and to methods of manufacturing a pre-heater assembly for pre-heating a fluid.
In liquid chromatography, a fluid (such as a mixture between a fluidic sample and a mobile phase) may be pumped through conduits and a column comprising a material (stationary phase) which is capable of separating different components of the fluidic sample. Such a material, so-called beads which may comprise silica gel, may be filled into a column which may be connected to other elements (like a sampling unit, a flow cell, containers including sample and/or buffers) by conduits.
For operating a fluid separation apparatus, the fluid can be pre-heated by a pre-heater assembly located downstream of an injector for injecting the fluidic sample in the mobile phase and upstream of the column.
GB 2432800 discloses a chromatographic system and method which include a passive pre-heater assembly. A fluid mixture is supplied from an injector to the pre-heater assembly and then to a chromatographic column having an active heating source. The pre-heater assembly includes a convoluted tube with first and second ends and a fluid passage extending centrally therebetween, first and second end fittings attached respectively to the first and second ends of the convoluted tube, and a thermally conductive film attached to an outer surface of the convoluted tube. The first end fitting is adapted for fluidly connecting the first end of the convoluted tube to the injector and the second end fitting is adapted for fluidly connecting the second end of the convoluted tube to the chromatographic column. The thermally conductive film conveys heat from an active heating source of a chromatographic column to the convoluted tube when the pre-heater assembly is positioned adjacent to the active heating source. The central fluid passage in the convoluted tube has a series of bends which function to create a secondary fluid flow field that is substantially orthogonal to a primary flow field established when fluid is traversing the fluid passage in the tube.
However, when fluid is pre-heated in a conventional pre-heater assembly of a fluid separation apparatus, the heat transfer to the fluid is in many cases not satisfactory.